Electric process for drying timber.



A. .U. ALGOOK.

ELECTRIC PROCESS FOR DRYING TIMBER.

7 APPLICATION FILED NOT-1, 1910.

Patented Oct. 31, 1911;

' UNITED STATES ALFRED UPTON ALCOGK,- 0F PERTH, WESTERN,AU STRALIA', AUSTRALIA.

ELECTRIC PROCESS FOR DRY ING TIMBER.

Specification of Letters Patent.

Patented Oct. 31, 1911.

Application filed November 4, 1910. Serial No. 590,653. I

To all whom it may concern:

Be it known that I, ALFRED UP'roN ALoocK, a subject of the King of Great Britain, and residing at Perth, Western Australia, Gommonwealth of Australia, have invented new and useful Improvements in Electric Processes for DryingTimber, of which the following is a specification.

This invention relates to an improved electric process for drying timber. Whereas it has been found in course of experiment that by the application of metal electrodesone at either end of a piece of timber there is a tendency with the electric current to burn or charthe timber at the points of contact with the electrode. This objection is particularly noticeable when high tension currents are employed. Hence to overcome the aforesaid difficulty a liquid electrode is employd especially when the logs are treated endwise while for stacked planks of timber lead electrodes introduced at intervals between them is used the latter drying being effected with a low potential current. Further when a low tension current is employed terminals madevof galvanized sheet metal, perforated plate or wire gauze or the like may be used. Also the process may be carried on in cacao or in drying chambers from which the surcharged air is removed and replaced with dry air all as hereinafter fully set forth.

The invention will now be described aided by a reference to the accompanying drawin s in which,

igure 1 is a front elevation partly in section of the process applied to short logs and; Fig.2 a planof same. Fig. 3 is a plan of the process as applied to planks and Fig. L a front view of same while Fig. 5 is an end view and Fig. 6 a side view partly in section of the process as applied to a large log.

When a liquid electrode is employed as shown in Figs. 1 and 2 to treat short logs of timber A they are stood in a flat dish or other suitable receptacle B formed of wood or metal and properly insulated containing a liquid electrode while a metal ring C sharpened on one edge for easy attachment is driven into the top of each log and forms a dish, which also is partly filled with a suitable liquid electrode and thus the timber being treated forms one side of the receptacles. Wires Don the end of which are pieces of iron E are immersed in the liquid lution of soda, sulfate of zinc, sulfate of copper or any other suitable electrolyte which may have a preservative effect on the timber. Solutions of resin, sugar, or creosote may be poured into the receptacle immediately after the sap has been driven out by the electricity. By means of an ammeter F contained in the circuit of the tim-- ber operated on the amount of moisture contained in the timber is indicated by the current passing. When the amlneter reading is m'l it is an indication that practically all the moisture has been dried out. When a liquid electrode is applied to large logs it may be done'in the manner shown in Figs. 5 and 6 in which a wood, metal or other suitis secured, one to each end of the tiniber,

so that the end of the log A forms one side of the receptacle and which is made water tight with the timber by means of rubber or othersuitable packing H. The receptacle is held fast by" means of pointed .dogs I driven into the log and screwed tight by nuts J The current wire D and metal plate E being immersed in the liquid as before de scribed.

In treating stacked planks of timber A as shown in Figs. 3 and 4 in place of applying an electrode one at each end of a length of timber as before described and which would necessitate a high potential, a number of metal electrodes preferably lead sheet are clamped at suitable intervals on the side of the plank or board so that by grouping the electrodes a reduction in resistance between the terminals of the two groupsis efiected and hence lower potential current may be employed. For example a stack of boards 12 feetlong 12 inches wide by two able receptacle G filled with liquid electrodeinches. thick-would have four sets of elec-' trodes, K K K K respectively equally spaced and clamped firmlyon thefa'ce of and lying between the boards one group comprising the K and K plates and the other group the K and K plates.. The, number of boards or planks which may be v for a twelve inch face board were approximately ten inches wide by twelve inches-to fourteen inches long the latter length so as to project beyond the top and bottom edges of the planks to facilitate connecting with the'electric wires. The lead strips should be sufliciently thick to allow suficient space between the boards for the free exit of the sap and for circulation of air which maybe advantageous to absorb liberated moisture. The air may be circulated by fans, blowers or cxhausters or as in the recent trials forced into a chamber containing the timber under pressure up to 500 pounds pressure or over if necessary. In carrying out the invention with a low tension current the terminals may be Inadeof such as galvanized sheet metal, perforated plate or wire gauze or the like one terminal beingsccured by tacking or otherwise to each end of the log or piece of timber which to be operated upon. Then in some instances the terminals may be supplied at 400 volts when in about three hours the timber will be completely heated by the passage of the electric current through it and aquantity of moisture will be seen oozing out between the end of the plates and the timber and at the sides of the latter also by means of an ammeter arranged in the circuit the amount of moisture contained in the timber is indicated and when the ammeter reading is m'l practically all moisture will have been dried out.

In a modification of the process the operation may be carried out in 'vacuo to expedite the withdrawal of the moisture and if desired combined with a simultaneous impregnation of creosote or other suitable preservative or further when drying timber in a chamber where the timber is electrically operated on the air which becomes charged neonate with moistaute is withdrawn by such as a pump anddry air fed to take its place until the latter becomes charged with moisture when it is again pumped out and so on until the timber is dry. y

The invention as. described in connection with Figs. 5 and 6 may be applied direct to logs of timber when newly cut in the forest and whenthe sap is fresh while to apply the invention direct to the trees as standing in the forest one terminal of the electric generator. would be earthed and the other terminal applied to the top of the tree trunk by means of spikes or the other suitable electrodes herein set forth.

What I claim as my-invention and desire to secure by Letters Patent is' 1. In an electric apparatus for drying timber, in combination, liquid electrodes adapted to engage the ends of the timber to be dried, a source of electricity and conducting wires leading from said source of electricity, the free ends of said wires being immersed in said liquid electrodes to form a circuit. v p

2. In an electric apparatus for drying timber, in combination, liquid electrodes adapted to engage the ends of the timber to be dried, a source of electricity, conducting wires leading from said source of electricity, the free ends ofsaid wiresbeing immersed in said liquid electrodes to form a circuit and an ammeter in said circuit.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALFRED UPTON ALCOCK. Witnesses: RICHARD SPARROW,

VIoToR DEVERELL. 

